The Right Chemistry: What Chanel No. 5 and TNT have in common | Montreal Gazette

One of the most fascinating facets of chemistry is the process of discovery. Think of TNT and chances are you think BOOM, not Chanel No. 5. But Trinitrotoluene played a major role in the formulation of one of the world’s most famous fragrances.

The Right Chemistry: What Chanel No. 5 and TNT have in common

One of the most fascinating facets of chemistry is the process of discovery. Think of TNT and chances are you think BOOM, not Chanel No.5. But Trinitrotoluene played a major role in the formulation of one of the most famous fragrances in the world.

Fragrances like Chanel No. 5 owe their aromas to discoveries made by chemists working on TNT. Pierre Obendrauf / Montreal Gazette files

One of the most fascinating facets of chemistry is the process of discovery. Think of TNT and chances are you think BOOM, not Chanel No. 5. But Trinitrotoluene played a major role in the formulation of one of the world’s most famous fragrances.

After William Henry Perkin’s 1856 accidental discovery of mauve, the world’s first synthetic dye, the chemical industry was hot on the trail of new colourants. It was then that German chemist Joseph Wilbrand synthesized TNT, which never made it as a yellow dye but did announce itself with a bang. At the time, trinitrophenol, commonly known as picric acid, was the most widely used high explosive, but was prone to accidental detonation during production and transport. TNT, on the other hand, can be melted and poured into shell or bomb casings with safety. Its detonation requires the use of a more sensitive explosive such as lead azide, which, when energetically struck, quickly decomposes to elemental lead and nitrogen gas. The shock wave created by the rapidly expanding nitrogen sets off the TNT. This same chemistry is used in automobile airbags where sodium azide supplies the nitrogen needed to inflate the bag.

When TNT detonates, it also releases nitrogen along with steam and carbon monoxide. It is the rapid production and expansion of these gases that characterizes an explosion. While TNT never made it as a dye for fabrics, during the First World War, it did manage to taint the skin of munitions workers, most of whom were women. “Canary girls,” these ladies came to be called. Skin discoloration, however, wasn’t the only problem. TNT can be absorbed through the skin and cause nausea, loss of appetite and liver problems. Many workers suffered before it was discovered that application of grease to the skin would prevent absorption.

After the explosive potential of TNT was recognized, chemists went to work trying to get more bang for the buck by attempting to modify the compound’s molecular structure. And that is just what Albert Bauer was doing in 1888 when he used the well-known Friedel-Crafts reaction to add a four-carbon fragment known as a “tertiary butyl” group to the molecule. As the reaction proceeded, he noted that the lab filled with a decidedly unusual smell. Being a chemist, Bauer was familiar with all sorts of odours, and this one reminded him of the fragrance of musk. That was an exciting observation because at the time musk scent was a much sought-after commodity, highly prized by the perfume industry. Not only did it lend a pleasing note to a perfume, but it also acted as a “fixative,” slowing down the evaporation of all the perfume’s components.

Musk scent was very expensive because of the scarcity of its source, the sex glands of the Asian male musk deer. The animal secretes a smelly mixture of compounds from the glands located near its anus to attract the female. In its concentrated form, the scent is decidedly unattractive, but becomes seductive when diluted. It remains a mystery how anyone ever discovered that the dried and then diluted secretions from this inconspicuous little abdominal sac of the male musk deer charmed receptors in our nasal passage. What we do know, however, is that musk fragrance has been used by perfumers since antiquity, with the word “musk” itself deriving from the Sanskrit word for testicle. The ancient Hindus seemingly were better at perfume-making than anatomy, since the scent glands are quite distinct from the animal’s testes.

As soon as Bauer sniffed the musky aroma of his new compound, he recognized that he was on to something. He quickly filed a patent for “Musk Bauer,” and proceeded to make other “nitro musks” with even more effective scents. Musk xylene, musk ketone and musk ambrette revolutionized the perfume industry and made Bauer a rich man. The nitro musks became the cornerstone of the perfume industry, accounting for the popularity of perfumes such as Chanel No. 5 introduced in 1921 and L’Air du Temps in 1948. They were mainstays until the 1980s, when they were dropped because of concerns about their poor biodegradability, neurotoxicity and tendency to cause a skin rash when exposed to sunlight.

Marilyn Monroe apparently wasn’t worried about exposure to sunlight in her bedroom. When asked what she wore to bed at night, she famously replied, “Why, Chanel No. 5 of course!” Quite an explosive remark in those days.